Description of the larva and puparium of Paragus absidatus Goeldlin ...

Rotheray & Sarthou: Early stages of Paragus absidatus103Description of the larva and puparium of Paragusabsidatus Goeldlin de Tiefenau, 1971 (Diptera, Syrphidae)Graham E. Rotheray and Jean-Pierre SarthouRotheray, G.E.; Sarthou, J.P. (2007): Description of the larva and puparium of Paragusabsidatus Goeldlin de Tiefenau, 1971 (Diptera, Syrphidae). – Volucella 8, 103-108.Stuttgart.The larva and puparium of Paragus absidatus are described from specimens collectedamong aphids on a Gentiana punctata plant located in the Vallée d'Ossau of theFrench Pyrenees. The early stages of this species are compared with those of the fourother European species with early stages described. Characters thought to distinguishParagus early stages are supported by P. absidatus which, like other Paragus larvae,has the dorsal and lateral margins of the body coated in tapering, fleshy projectionsand a row of four similar projections below the posterior breathing tube. The larva ofP. absidatus is most similar to that of P. pecchiolii Rondani. It is distinguished fromthat species by the upright, triangular-shaped vestiture coating the integument of thelarva and puparium.Key words: Paragus, larva, Europe, Syrphidae.ZusammenfassungLarve und Puparium von Paragus absidatus werden nach Exemplaren beschrieben,die zwischen Blattläusen an Gentiana punctata im Vallée d'Ossau in den französischenPyrenäen gefunden wurden. Sie werden verglichen mit den vier europäischen Paragus-Arten, von denen ebenfalls Jugendstadien bekannt sind. Wie die Larven der anderenParagus-Arten ist auch die von P. absidatus durch sich verjüngende fleischige dorsaleund laterale Fortsätze charakterisiert; eine Reihe von vier solchen Fortsätzen befindet sichauch unter dem Stigmentubus. Die Larve von P. absidatus ähnelt der von P. pecchioliiRondani, unterscheidet sich von dieser aber durch die aufrechte, dreieckige Behaarungdes Integuments von Larve und Puparium.IntroductionIn Europe about 20 species of the distinctive yet enigmatic hoverfly genus, ParagusLatreille, are known. Several new species have been added in recent years (Speightet al. 2005). The larvae are predators, mostly of soft-bodied Homoptera (Goeldlin deTiefenau 1974). Adults are readily distinguished by their small size being less than 5 mm

Rotheray & Sarthou: Early stages of Paragus absidatus107Comparing larval and puparial descriptions and figures of P. albifrons, haemorrhous,pecchiolii and quadrifasciatus in Goeldlin de Tiefenau (1974) with the larva and pupariumof P. absidatus studied here, the early stages of the latter species are most similar toP. pecchiolii. Both species have the projection bearing sensilla 2 on abdominal segments1-7 about as equally long as that bearing sensilla 1 and the projections bearing sensilla1 on the seventh abdominal segment are so approximated that their bases are touching.Neither of these characters appear to be present in the early stages of other Paragusspecies in which the projection bearing sensilla 2 is usually shorter than those bearingsensilla 1 and the projections bearing sensilla 1 on the seventh abdominal segment areseparate.The early stages of P. absidatus appear to be distinguished from those of P. pecchioliiby the vestiture. The vestiture of P. absidatus is relatively large and conspicuousconsisting of upright, triangular-shaped setae whereas that of P. pecchiolii appears toconsist of inconspicuous nodules (Goeldlin 1974).The functional significance of similarities and differences in the states of dorsalprojections and vestiture in Paragus larvae are difficult to assess. However, if they arefunctional, they are most likely to have been affected by crypsis (Rotheray 1986). Itis possible that crypsis against background features of aphid host plants may explaindifferences observed between Paragus larvae.ReferencesDixon, T.J. (1960): Key to and descriptions of the third instar larvae of some species of Syrphidae (Diptera)occurring in Britain. – Transactions of the Royal Entomological Society of London 112, 345-379.Goeldlin de Tiefenau, P. (1974): Contribution a l'étude systématique et écologique des Syrphidae (Dipt.) dela Suisse occidentale. – Mitteilungen der Schweizerischen Entomologischen Gesellschaft 47, 151-252.Goeldlin de Tiefenau P. (1976): Révision du genre Paragus (Dipt., Syrphidae) de la région paléarctiqueoccidentale. – Mitteilungen der Schweizerischen Entomologischen Gesellschaft 49, 79-108.Hartley J.C. (1963): The cephalopharyngeal apparatus of syrphid larvae and its relationship to other Diptera.– Proceedings of the Zoological Society of London 141, 261-280.Marcos-Garcia, M.A. (1986): Citas de interes del genero Paragus Latreille, 1804 en la Peninsula Iberica ydescripcion de Paragus vandergooti sp.nov. (Diptera, Syrphidae). – Actas de las VIII Jornadas A e E,765-772.Marcos-Garcia, M.A.; Rojo, S. (1994): Paragus hyalopteri n.sp. an aphidophagous hoverfly (Dipt.: Syrphidae)attacking the mealy plum aphid (Hom: Aphididae). – Entomophaga 39, 99-106.Rotheray, G.E. (1986): Colour, shape and defence in aphidophagous syrphid larvae (Diptera). – ZoologicalJournal of the Linnean Society 88, 201-216.Rotheray, G.E. (1993): Colour Guide to Hoverfly Larvae (Diptera, Syrphidae). – Dipterists Digest No. 9,1-156.Rotheray, G.E.; Gilbert, F.S. (1989): The phylogeny and systematics of European predacious Syrphidae(Diptera) based on larval and puparial stages. – Zoological Journal of the Linnean Society 95, 29-70.Rotheray, G.E.; Gilbert, F.S. (1999): Phylogeny of Palaearctic Syrphidae (Diptera): Evidence from larvalstages. – Zoological Journal of the Linnean Society 127, 1-112.Sommaggio D. (2002): Paragus gorgus Vujić & Radenković, 1999: a junior synonym of P. majoranae Rondani,1857, and reinstatement of P. pecchiolii Rondani, 1857 (Diptera, Syrphidae) – Volucella 6, 53-56.Speight, M.C.D.; Castella, E.; Sarthou, J.P.; Monteil, C. (2006): Syrph the Net on CD. Issue 5. The databaseof European Syrphidae. Dublin (Syrph the Net Publications).

108Volucella 8, 2007Addresses of authors:Graham E Rotheray, National Museums of Scotland, Chambers Street, Edinburgh EH11JF UK. E-mail: g.rotheray@nms.ac.ukJean-Pierre Sarthou, UMR Dynafor, INP-ENSAT, BP 32607, 31326 Auzeville-Tolosanecedex, France. E-mail: sarthou@ensat.fr